Influence of plasma sputtering treatment on natural dyeing and antibacterial activity of wool fabrics

In this paper, the effect of plasma sputtering treatment on the natural dyeing properties of wool and the possibility of substituting it for mordant treatment have been studied. We used madder and weld as natural dyes and copper sulfate (CuSO₄) as a metal mordant. We also used, copper as the electrode material, in a DC magnetron plasma sputtering device.     

Photocatalytic and antibacterial characteristics of decorated polyester textile with ceramic nanoparticles of cobalt ferrite

In this study, a multifunctional textile profiting from photocatalytic activity, magnetic, and antibacterial properties was generated through decorating polyester fabric with cobalt ferrite (CoFe₂O₄) nanoparticles using the co-precipitation technique. The X-ray diffraction (XRD) results supported the successful decoration of fabrics with CoFe₂O₄ magnetic nanoparticles. Field emission electron scanning microscopy (FESEM) images accompanied by energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses demonstrated the morphology, dispersion, and chemical structure of particles on the surface. The mean particle size of cobalt ferrite was measured to be approximately 40 nm. Vibrating sample magnetometer (VSM) results confirmed the ferrimagnetic behavior of the decorated fabrics with saturation magnetization (M_s) and coercivity (H_c) of 1.8 emu/g and 1902 Oe, respectively. The UV–vis diffuse reflectance spectrum (DRS) and photoluminescence (PL) data indicated the appropriate performance under visible light irradiation and postponed electron-hole recombination of the decorated fabric, respectively. The maximum MB degradation efficiency of 97% after 180 min of visible light illumination was obtained. The active species trapping analyses indicated that hydroxyl radicals (^●OH) were the effective species in the photocatalytic degradation mechanism. The decorated sample with the best photocatalytic activity revealed more than 99% reduction in the number of colonies against gram-negative and gram-positive bacteria after 24 h contact time, which validated its excellent potential for antibacterial applications. Outstanding photocatalytic and antibacterial characteristics of the decorated textile with cobalt ferrite nanoparticles turn it into promising composite material for self-cleaning purposes.     

Deposition and characterization of AZO thin films on flexible glass substrates using DC magnetron sputtering technique

Al-doped zinc oxide (AZO) thin films were deposited onto flexible ultra-thin glass substrates by using a direct current (DC) magnetron sputtering process. The effects of sputtering power, working pressure and substrate temperature on the morphology and optoelectronic performances of AZO films were investigated. The optimal sputtering power, working pressure and substrate temperature for AZO film were determined to be 100 W, 0.9 Pa and 150 ℃, respectively. Further increasing or decreasing the sputtering power, working pressure and substrate temperature degrades the quality of AZO films. XRD patterns show all as-sputtered AZO thin films are preferred to grow along <0002> direction. Moreover, the largest grain size, which depicts the best microstructure of AZO films, matches with the smallest stress value. It can be seen from SEM images that the surface is smooth and dense. The smallest value of the resistivity is 1.784×10⁻³ Ω cm and the average transmittance of all AZO films in the visible range is about 80%. The X-ray photoelectron spectroscopy spectra show that the amount of Al element in the AZO film is very small.     

Fabrication of binary metal substituted CdO with superior aptitude for dye degradation and antibacterial activity

With the widespread increase in the emergence of antibiotic-resistant bacterial strains and extent of the water contamination by organic pollutants, a considerable effort is required for the development of effective and safe materials to treat infections and remove water pollutants. Herein, we have developed doped and co-doped cadmium oxide CdM₁M₂O (M₁ = Mn, M₂ = Al, Sr, Ba) nanostructures with antibacterial activity against three bacterial strains (Staphylococcus aureus, Klebsiella pneumoniae, and Proteus vulgaris) and photocatalytic activity against methylene blue dye under direct sunlight irradiation. A very inexpensive and simple wet chemical approach was employed to fabricate the doped and co-doped nanostructures. The results of the antibacterial tests on Klebsiella pneumoniae, Staphylococcus aureus, and Proteus vulgaris bacteria indicated that all the prepared nanostructures possessed superb antibacterial properties. The Cd_1-(x+y) Mn_xAl_yO nanostructures exhibited excellent degradation efficiency with typical organic dye (methylene blue) within 1 h of direct sunlight irradiation. The efficient synergistic antibacterial and photocatalytic activities coupled with their recyclability demonstrated the potential of Cd_1-(x+y) Mn_xAl_yO nanostructures for practical use in polluted water remediation and environmental protection applications. The simple method used for synthesizing the nanostructures to enhance their antibacterial and photocatalytic activities can potentially be extended to fabricate other photocatalysts and antibacterial agents.     

Enhanced photocatalytic activity of Au-buffered TiO2 thin films prepared by radio frequency magnetron sputtering

Au-buffered TiO₂ thin films have been prepared by radio frequency magnetron sputtering method. The structural and morphological properties of the thin films were characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The photocatalytic activity of the samples was evaluated by the photodecomposition of methylene blue. The Au-buffer thin layer placed between the TiO₂ thin films significantly enhanced photocatalytic activity by 50%. Annealing the Au-buffered TiO₂ thin film at 600 °C decreased the film roughness, but it increased the surface area and anatase crystalline size, enhancing the photocatalytic activity.     

超疏水PET织物的制备及其抗菌性能

纺织物表面的超疏水特性将赋予其优异的自清洁性能。以PET无纺布为基材,探索了利用溶胶-凝胶法在预处理后的PET织物表面构筑具有微纳结构的超疏水涂层的方法;并利用扫描电镜（SEM）、接触角测量仪表征了改性PET织物表面的微观结构和润湿性。进一步地,分别以大肠杆菌和金黄色葡萄球菌为试验菌株,通过细菌转移法和抑菌圈法评价与分析了改性PET织物表面的抗菌性能。研究表明：利用改进的Stöber溶胶-凝胶过程能够在经碱减量法预处理的PET表面原位形成SiO₂纳米粒子;再用含疏水性长链的十二烷基硅烷对这一表面进行改性,并经过表面热处理,就能够成功地在PET织物表面构筑多层次的微/纳结构,从而制得表面具有超疏水特性的PET织物,其接触角可达到163°。这一超疏水PET织物能够抑制细菌在其表面的生长繁殖,表现出了明显的抗菌特性。     

Plant mediated green synthesis and antibacterial activity of silver nanoparticles using Crataegus douglasii fruit extract

In this study, silver nanoparticles were synthesized using the Crataegus douglasii fruit extract as a reducing agent. The reaction process was monitored by UV–vis spectroscopy. Further characterization was carried out using scanning electron microscopy (SEM). To optimize the biosynthesis of silver nanoparticles, the effect of process variables such as extract concentrations, mixing ratio of the reactants, time and pH were also investigated. The SEM images showed silver nanoparticles with 29.28 nm size and nearly spherical shape at 24 h interaction time. The antibacterial activity of the synthesized silver nanoparticles was confirmed against Staphylococcus aureus and Escherichia coli.     

加成型硅橡胶铂催化剂的制备及其活性研究

合成了几种不同的铂催化剂 (氯铂酸二乙烯基四甲基二硅氧烷 ,氯铂酸 -异丙醇 ,氯铂酸 -邻苯二甲酸二乙酯 )。考察了其对于有机硅橡胶加成聚合反应的催化活性 ,并从催化机理的角度初步探讨了催化剂不同活性差异的原因     

Effect of bonding systems and antioxidants on the adhesion between EPDM rubber and polyester fabric

Ethylene propylene diene monomer (EPDM) rubber mixes containing different types of bonding materials and various commercial antioxidants were used to evaluate the adhesion of EPDM rubber to polyester fabric. A new antioxidant was prepared by graft copolymerization of 1, 5-diaminonaphthalene (DAN) onto natural rubber (NR) in order to investigate its effect on adhesion. It was observed that EPDM mixes containing DAN grafted onto NR shows better adhesion levels than those containing commercial antioxidants. It is also clear that the new system has high resistance towards aging and ionizing radiation. The new NR-g-DAN acts not only to stabilize the rubber mix towards environmental conditions but also to improve adhesion to polyester fabric.     

Superior antibacterial activity against seed-borne plant bacterial disease agents and enhanced physical properties of novel green synthesized nanostructured ZnO using Thymbra spicata plant extract

An easy and eco-friendly approach using Thymbra spicata var. spicata L. (TS) plant extract was developed for the formation of nanostructured ZnO. TS aqueous leaf extract was used for the green synthesis of nanostructured ZnO via the Successive ionic layer adsorption and reaction (SILAR) method. Electron microscope images exhibit the morphological adjustments of the samples with respect to change in TS concentration in the growth solution. The nanostructured ZnO grown by SILAR was observed to be polycrystalline with hexagonal crystal structure. The optical energy bandgap value of the samples varies from 3.21 to 3.09 eV as the content of TS increases from 2.5 to 5.0%. Also, the effect of TS additive to ZnO on electrical properties was investigated. It was determined by Van der Pauw measurements that TS contribution to ZnO significantly increased electrical resistance. In addition, impedance analyzes of the produced films were carried out in the frequency range of 20Hz ?1 MHz. Nyquist plots showed the single semicircle for all samples, and the values of capacitance and resistance were calculated. Its antibacterial activities was investigated against economically important Gram-positive (Clavibacter michiganensis subsp. Michiganensis) and negative (Pseudomonas syringae pv. Phaseolicola, Pseudomonas cichorii and Pectobacterium carotovorum subsp. Carotovorum) seed-borne plant bacterial disease agents by using paper disc diffusion assay for the first time. In vitro laboratory screenings of green synthesized nanostructured ZnO have given encouraging results, indicating their potential use in the management of seed-borne bacterial diseases.     

Construction of g-C3N4/TiO2/Ag composites with enhanced visible-light photocatalytic activity and antibacterial properties

In this study, the multifunctional carbon nitride based composite graphitic-C₃N₄ (g-C₃N₄)/TiO₂/Ag was prepared through a simple and efficient vacuum freeze-drying route. TiO₂ and Ag nanoparticles were demonstrated to decorate onto the surface of g-C₃N₄ sheet. In the ultraviolet–visible absorption test, a narrower band gap and red-shift of light absorption edge were observed for g-C₃N₄/TiO₂/Ag compared to pristine g-C₃N₄ and single-component modified g-C₃N₄/TiO₂. The photodegradation property of g-C₃N₄/TiO₂/Ag was investigated toward the degradation of methylene blue (abbreviated as MB) under the irradiation of visible light. These results indicated that the degradation performance of organic dyes for g-C₃N₄/TiO₂/Ag was obviously improved compared with g-C₃N₄/TiO₂ and g-C₃N₄. The reaction rate constant of MB degradation for g-C₃N₄/TiO₂/Ag was 4.24 times higher than that of pristine g-C₃N₄. In addition, such rationally constructed nanocomposite presented evidently enhanced antibacterial performance against the Gram-negative Escherichia coli. Concentration dependent antibacterial performance was systematically investigated. And 84% bacterial cell viability loss had been observed at 500 μg/mL g-C₃N₄/TiO₂/Ag within 2 h visible light irradiation.     

Studies on PVA/AgI-based polymeric membranes for exploration of antibacterial activity

In the present communication, solid polymer electrolyte films have been prepared using solution cast technique based on polyvinyl alcohol (PVA) as host polymer and silver iodide (AgI) as salt. The objective of the study is to develop PVA electrolytic films with AgI and evaluate to protect against simulants of biological warfare agents. The antibacterial activities of the films are explored against Aeromonas hydrophila, Escherichia coli, Salmonella typhii, and Shigella boydii. The antibacterial effects of the PVA/Ag⁺ hybrids were assessed by the minimum inhibitory concentration method. Polymer electrolyte films show good antibacterial activity against A. hydrophilla, S. typhii, and S. boydii. Scanning electron microscopy is used to study the surface morphology of the polymeric membranes. Complex impedance spectroscopy is used for characterizing the electrical and dielectric properties of the electrolyte samples. Frequency-dependent various dielectric properties such as dielectric constant, dielectric loss, and loss tangent have been discussed. The variations of AC conductivity gives the explanation in understanding the mechanism of the ion transport and determine power exponent value n lying in the range 1 and 1.2 which represents the trapping of ions in the polymer matrix.     

Influence of radio frequency magnetron sputtering parameters on the structure and performance of SiC films

Amorphous SiC films fabricated by Radio frequency (RF) magnetron sputtering have been widely used due to their excellent properties including high strength, good hardness and outstanding abrasion resistance. However, most researches set a lower target-substrate distance, which limits its large-scale coating for practical industrial application. In this work, the distance between the target and substrate was enlarged to 120 mm, and the effective coating area was about four to ten times than other researches. Furthermore, the effects of sputtering power, deposition pressure, substrate temperature and bias voltage on the structure and performance of SiC films were also investigated. Finally, SiC films with high elasticity modulus (310.8 GPa) and hardness (35.6 GPa) are obtained by RF magnetron sputtering.     

The effect of humidity, fabric surface geometry and dye type on the colour of cotton fabrics dyed with a select range of anionic dyes

Four C.I. Solubilised Sulphur dyes were applied to cultivated silk fabric using sodium thioglycolate at pH 7, for 30 min at 60 °C in the absence of electrolyte. Medium/deep shades were obtained that displayed good/excellent fastness to washing at 40 °C and little or no sensitivity to oxygen bleach fading. The dry rub fastness of the dyeings ranged from moderate to good whilst the wet rub fastness varied from poor to moderate; light fastness of the 10% omf dyeings varied from low to moderate. The mild application conditions used had little effect on the tensile strength of the fabric.     

Self-aggregation and antibacterial activity of N-acylated chitosan

Chitosan was selectively N-acylated with acetic, propionic and hexanoic anhydrides under homogeneous condition to prepare N-acetyl chitosan (NACS), N-propionyl chitosan (NPCS) and N-hexanoyl chitosan (NHCS), respectively. NACSs with different N-acetylation degrees were obtained by controlling the degree of N-acetylation. The chemical structures of N-acylated chitosans including degree of deacetylation (DD), weight-average molecular weight (M_w), radius of gyration (〈S₂〉_Z^1/2) and crystal structure were studied by FTIR, GPC-LLS and X-ray diffraction techniques. Aggregation behavior of N-acylated chitosan was investigated by rheometer. Intramolecular aggregation of NPCS and NACS was stronger with NPCS stronger than NACS. The effect of concentration of polymer, concentration of salt and temperature on self-aggregation of NACS and NPCS was investigated. Hydrophobic interaction of N-acylated chitosan substituted with longer acyl chains was stronger. With moderate DD, intramolecular aggregation occurs predominantly. In vitro antibacterial activity test of N-acylated chitosans was evaluated against two Gram-positive bacteria and two Gram-negative bacteria. Relative inhibition time (RIT) of NHCS with concentration of 1 mg/ml against Escherichia coli and Pseudomonas aeruginosa was more than 2-6 times longer than that of NACS and NPCS. N-acylated chitosan with lower DD had inhibitory effect on the growth of bacteria than that with moderate DD. The results showed that intermolecular aggregation characteristic of N-acetylated chitosans with low DD may help in forming bridge to interact with bacterial cell.     

Facile synthesis,characterization and antibacterial activity of nanostructured palladium loaded silicon carbide

In this work, noble metal (Palladium) loaded silicon carbide (SiC) nanoparticles have been successfully synthesized using a single step synthetic route and its antibacterial action against gram-negative (E. coli) and gram-positive (S. aureus) bacteria have been investigated. The structural and morphological characterizations of pure SiC and Palladium (Pd) loaded SiC nanoparticles were carried out by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Energy dispersive x-ray spectroscopy (EDX), Elemental mapping and Transmission electron microscopy (TEM). The characterizations results offer substantial proof that the SiC surface was successfully decorated by Pd. Furthermore the EDS analysis reveals that the product contained Pd as well as W and O, thus reaffirming the production of Pd loaded SiC nanoparticles. The MICs and MBCs values examined by standard agar dilution methods show that MICs and MBCs values of pure SiC were >?16 and >?32?mg/ml, respectively against E. coli and S. aureus, whereas Pd loaded SiC nanoparticles exhibited MIC and MBC value of 4?mg/ml and 8?mg/ml, respectively. The morphological and structural alterations caused by SiC and Pd loaded SiC nanoparticles on E. coli and S. aureus cells were further investigated by SEM analysis. A noteworthy improvement in antibacterial performance was observed, when E. coli and S. aureus cells were exposed to Palladium (Pd) nanoparticles (NPs) loaded silicon carbide (SiC). The results obtained show a significant impact by loading Pd on SiC in the deactivation of microorganisms in vitro.     

Development of g-C3N4/ZnO nanocomposite as a novel,highly effective and durable photocatalytic antibacterial coating for cotton fabric

Photocatalytic antibacterial coats are considered among the best solutions to bacterial contamination of fabrics, with the drawback of reduced efficacy after continued use and washing. In the present study, the g-C₃N₄/ZnO (CNZ) nanocomposite has been introduced as a novel cotton fabric coating, with high durability, and CNZ nanopowders were synthesized using a two-step thermal synthesis process and directly coated onto cotton fabric using the sonication technique. The synthesized nanoparticles (NPs) were examined using X-ray diffraction (XRD), UV–visible spectroscopy, photoluminescence (PL), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) analyzes. Besides, the SEM analysis confirmed the successful deposition of NPs on cotton fabric. The photodegradation of methylene blue (MB) stain was assessed as a functional test for the photocatalytic effectiveness of the coated fabric, then its antibacterial properties were evaluated under visible light, by direct contact with bacterial suspensions and culturing. The results revealed that the CNZ-coated cotton fabric containing 30% ZnO (CNZ-30) has significant photocatalytic antibacterial activity against both Escherichia coli (gram-negative), and Staphylococcus aureus (gram-positive) bacteria. The bacterial reduction rate of CNZ-30 coated fabric for both E. coli and S. aureus was above 98%, even after 18 washing cycles. This excellent performance is attributed to the effective coupling of ZnO with g-C₃N₄, improved light absorption, and reduced e⁻/h⁺ pair recombination rates. This study novel coating method can offer an environmentally friendly, cost-effective, and simple process to manufacture hybrid CNZ antibacterial cotton in the textile industry.     

Effect of annealing temperature on the morphology and antibacterial activity of Mg-doped zinc oxide nanorods

Herein, magnesium-doped zinc oxide nanorods (MgZnO NRs) were synthesized by the co-precipitation method and annealed at different temperatures in the range of 100–500?°C. The increase in the annealing temperature was found to influence both chemical and morphological structures of the MgZnO NRs: Ultraviolet–visible diffuse reflectance spectroscopy showed an increase in band gap with increase in the annealing temperature. Fourier-transform infrared spectra showed that two characteristic peaks at 487?cm^?1 and 442?cm^?1 corresponding to a weak Zn–O stretching initially decreased and then disappeared with increase in the annealing temperature. Moreover, the MgZnO NRs annealed at 100?°C had large crystallite size, high aspect ratio, and narrow edges. Remarkably, the MgZnO NRs annealed at 100?°C exhibited the highest antibacterial activity against both S. aureus and E. coli strains, attributed to the high aspect ratio and diffusion ability of the Zn²⁺ ions and large surface charge, crystallite size, and surface area. The MgZnO NRs annealed at the relatively low temperature of 100?°C could be easily produced commercially, in large quantities, and effectively used to prevent the growth of foodborne microbes in food packaging applications.     

Enhanced antibacterial activity,antioxidant, and in vitro biocompatibility of modified polycaprolactone-based membranes

The fabrication, surface functionality, and biocompatibility of membranes prepared from blends of polycaprolactone (PCL) and curcumin powder (CURP) (PCL/CURP) were studied. Acrylic acid (AA)-grafted polycaprolactone (PCL-g-AA) was evaluated as an alternative to PCL. Mouse tail-skin fibroblasts (FBs) were seeded on two series of these films to assess cytocompatibility. Collagen and cell proliferation analyses indicated that PCL, PCL-g-AA, and their composite membranes were biocompatible with respect to FB proliferation. However, FB proliferation, collagen production and the percentage of normal cells growing on PCL/CURP membranes were greater than those for PCL-g-AA/CURP membranes. Rapid apoptosis was not observed with assays of FBs on the PCL-series membranes, demonstrating the potential of PCL/CURP or PCL-g-AA/CURP membranes for biomedical applications. Moreover, CURP enhanced the Escherichia coli (BCRC 10239) antibacterial activity and antioxidant properties of the membranes. Membranes of PCL-g-AA or PCL containing CURP had better antibacterial and antioxidant activity.     

Preparation and antibacterial activity of Ag/TiO2-functionalized ceramic tiles

An Ag/TiO₂ coating was deposited onto glazed ceramic tiles by a sol-gel and spraying method at high temperatures. The coating was characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The results showed that silver was present in rutile-TiO₂, and the temperature did not change the phase composition of the samples. The Ag/TiO₂ coating had a higher roughness than the TiO₂ coating. The tape test (D 3359–08) showed that the coatings prepared at 950 °C and 1000 °C had good adhesion to the ceramic tile substrate. The antibacterial activity of the coating was tested by photocatalytic sterilization experiments. The results showed that the Ag/TiO₂ coating had a higher antibacterial activity than the TiO₂ coating, and the sterilization efficiency of Escherichia coli, Staphylococcus aureus, Shigella, and Salmonella exceeded 99.655% under 2 h of visible light irradiation. This research provides a method to create Ag/TiO₂ coatings with good thermal resistance, adhesion, and antibacterial activity. This improves the low photocatalytic activity caused by the anatase-to-rutile transformation of TiO₂ at high temperatures and the poor adhesion at low temperatures.